Torque wrench



Jan. 16, 1 945. 7

K. R. LARSON ETAL TORQUE WRENCH Filed Jan. 14, 1941 2 Sheets-Sheet 1 lV// /////Z Ai N .1 ADY. mw E TRR HM MM-W.$O v R 4 n N M. .A 1H. 0

Wm M Jan. 16, 1945. K L O ETAL 2,367,224

TORQUE WRENCH 2 Sheets-Sheet 2 Filed Jan. 14, 1941 IN VE N TORS. KENNETH R. LARSON. GEORGE M. WA

. RA VEN.

ATTORNEY.

FY5165. mm.

Patented Jan. 16,1945

UltlTED STATES PATENT OFFICE I 2,367,224

roaooe weapon V KennethR. Larsom Des Plaine's, 111., and George Walraven, Kenosha, Wis., assignors to e e Snap On Tools Corporation, Kenosha, Wis.

Application January 14, 1941, Serial No. 374,362 i7 Claims. (01. 73 -139) This invention relates to' turning devices and more particularly to nut turning wrenches, although certain features thereof maybe employedwith equal advantage io'rother purposes. This application is a continuation-impart of pending application Serial Number 317,226. and filed February 5, 1940. v e

It contemplates more especially the provision of a simple, dependable, accurate and compact torque Wrench of the type described in the pending sole patent application Serial Number 317,226 and filed February 5, 1940'w-hich is being substituted by this joint application for Letters Patent. j 1

Numerous types .of torque turning wrenches have heretofore been proposed,lbut these have not proven entirely satisfactory, owing to their substantially increased bulk over ordinary nut turning tools and their failure to render a .dependable and uniform service in gauging the torque applied in any nut or other fasteningexpedient such as a screw. There has been a long would require the discretion and judgment of the attendant as well as entail some time observ= ing the indicator. Withthe teachings'oi the present invention, this disadavntage is avoided by providing signal means that are energized at the very instant that there is a torque cominensurate with the setting of saidcalibrated indicating means to close the circuit to an elec trically operated signal. Such signal means in conjunction with an extremely sensitive switch that is rendered responsive to the indicator, inomentarily registers the predetermined force that is being applied in turning operations without any careful observation or entailment of any time. Thisis also conducive to uniform results in the turning of nuts and other fastening ex-- pedients with a turning tool of the type mentioned both for test and production purposes.

One object of the present invention is to sunplify the construction and improve the operation i of devices of the character mentioned.

felt want for a torque turning tool that issimple,

compact," dependable, accurate, and instantly indicates the desired tension or registersxany predetermined or pre-set tension or torque applied or to be applied to a nut or other" fastening expedient. i

Them-too, great difliculty has been encountered in maintaining'the'indicating mechanism in good condition of operation due to the abuses occasioned during the normal use in nut turning operations. Should the applied torque be released by rupture in the fastener or by ac-' cidental release at the instance of the attendant, the recoil on the dial'meohanism and indicator is so rapid as to normall cause structural failures therein. This has been eliminatedin the preferred embodiment of the present invention by the-use of a clutch mount for the dialindlcator that permits free slippage with'reieren'ce to the dial mechanism and the provision of a beam extension which is highly flexible, resilient and possessed of only sufficient rigidity to overcome the load of. displacing the measuring instrumentalities connected thereto. Consequently, the severe stress and strains resultingir'om anyback-lash action, will be absorbed for the 4 most part by the fiexingof the beam extension and thus protect the measuring instrumentalities in any type of'beam device undersuch abnormal conditions of abusive operation. 7

' Then, too, full advantage of utilizing a torque indicating tool is riot'realized by a mere dial indicator, since in production operations such Another object is to provide a dial indicator clutch mount that affords slippage between the dial mechanism and the indicator to preclude damage thereto should the applied torquebe re leased by 'rupture in the fastener or by accidental release at't-he instance of the attendant.

Still another object is to provide a turning toolhaving torque indicating means in eon junction with an improved shock absorbing actuator therefor for predetermining the torque applied in any selected turning operation.

A further object is to provide ato'rque wrench having an improved measuring indicator ac tuator that enables ready adjustment to insure accurate measurements without entailing any appreciable time, labor or expense.

A still further object is to provide signal means in conjunction with a torque wrench that is rendered operative responsive to applying force commensurate with any adjusted torque t which the indicator is set.

. Suitable a further object is to provide accurate means for energizing signal means responsive to the application of force with a wrench or other turning tool, commensurate with the setting of calibrated indicating means.

An additional object is to provide a novelcomblnation of indicating elements in association with a wrench or other turning tool so as to signal the application of a predetermined the following illustrative embodiment of the present invention.

In the drawings:

Figure 1 is a front View in elevation of a wrench and dial embodying features of the present invention.

Figure 2 is a side view in elevation of a wrench and dial embodying features of the present invention;

Figure 3 is a rear view in elevation of a wrench and dial embodying features of the present invention.

Figure 4 is a sectional view taken substantially along line IV-IV of Figure 3.

Figure 5 is a sectional view taken substantially along line V-V of Figure 3.

Figure 6 is a sectional view taken substantially along line VIVI of Figure 3.

Figure 7 is a bottom View of the wrench shown in Figure 3with 'the bottom plate removed to illustrate the inner construction, the handle being broken away for convenience.

Figure, 8 is a sectional view taken substantially along line VIII-VIII of Figure 1.

Figure 9 is a sectional view taken substantially along line IXIX of Figure 2.

Figure 10 is a sectional View taken substantially along line X-X of the dial mechanism shown assembled in Figure 8.

Figure 11 is a sectional view taken substantially along line XL-Ifl of Figure 9.

Figure 12 is the bottom view of the calibrated dial.

Figure 13 is a sectional view taken substantially along line XIIL-XIII of Figure 9.

Figure 14 is a sectional View taken substantially along line XIV-XIV of Figure 1.

Figure 15 is a fragmentary sectional view of the pointer reset clutch assembly taken substantially along line XV-XV of Figure 1.

Figure 16 is a fragmentary sectional View in elevation taken substantially along line XVI- XVI of Figure 8.

The structure selected for illustration comprises a solid handle member I!) of standard construction having an elongated chambered wrench shank or body ll cast or otherwise shaped to present inclined side walls l2 and I3 to terminate in a semi-circular extremity I4. The handle H! with its chambered body H is preferably though not essentially cast from an aluminum alloy so as to possess the desired strength and lightness for convenience and manipulation in nut turning as will appear more fully hereinafter. It will be observed that the handle shank or body H consists of the inclined side walls l2l 3 which converge in the direction of the handle ID with an intermediate body wall l5 formed integral therewith to define an elongated chambered interior IS.

The shank II is normally covered by a solid plate I! that is shaped to conform with the configuration of the body wall I5 to confront therewith and serve as a complement of an open edge l8 that extends around the side walls l2l3 and their semi-circular extremity I4, the face plate I! being shaped to correspond therewith and its lower edge l9 cooperates with and abuts against the shoulder 20 (Figures Z-and 7) formed on the shank ll proximate to the solid handle In. A plurality of threaded screw fasteners 2! project through apertures in the plate [1 to engage correspondingly threaded bores 22 in the edge I8 that extends along the side walls l2l3 of the handle shank or body II and end 14,

thereby enclosing the chamber l6 and confining the torque resisting instrumentalities and measuring instrumentalities to be described hereinafter.

It will be noted that the handle shank or body 15 and especially the inclined side walls l2l3 are reinforced in the region of the threaded bores 22 by increasing the thickness of the cast metal as at 2324, 25-26 and 2'! which is a solid portion of the handle shank H'proximate to the lower extremity of the chamber I6 provided therein. The semi-circular head l4 of the body II is provided with a circular recess 28 corresponding in curvature therewith and measured to receive an accurately fitting revoluble member 29 of corresponding shape and size for rotary association therein. It is to be noted that the circular recess 28 communicates with the chamber I6 in the handle shank II, and the entire head portion is reinforced by the enlarged thicknesses 23-24 of the side Walls l2l3 in the region of the recess 28.

Now, then, the enlarged thicknesses 25-26 of the side walls l2l3 are approximately along a transverse median line of the handle l0 and its contiguous shank or body H, and these are circularly recessed to provide interrupted arcuate portions 30 and 3| which receive a cylindrical bearing or bushing 32 of pressed or other suitable material. The bushing 32 is provided with a diametrically disposed bore 33 which freely receives a closely fitting cylindrical rod 34 that extends therethrough from the revoluble member 29 to serve as a torque resisting beam.

To this end, the cylindrical elongated rod 34 is, in this instance, of uniform diameter and projects diametrically through the revoluble member 29 as at 35 for fixed engagement therewith to constitute a single'acting unit or member. As shown, the revoluble member 29 has a transversely disposed cylindrical extension 36 which is journalled in a correspondingly shaped aperture 31 provided in the cover plate H. The

, cylindrical extension 36 is, in this instance,

formed integral with the revoluble member 29 and terminates beyond the cover plate IT in a polygonal shank 38 for registry with a correspondingly shaped and sized recess formed in the wrench socket or other turning implement as commercial practice may dictate for use therewith.

It has been found more desirable, however, from a manufacturing standpoint to terminate the elongated cylindrical beam 34 just beyond the floating mount 32 thereof and join therewith a smaller elongated clutching pin 40 of comparatively smaller diameter for pressed fitting axial engagement in an end bore 4| provided in the free extremity of the elongated beam 34. The clutching pin 40 is pressed in the end axial bore 4| of the beam 34 to effect an integral joinder therewith. As shown, the clutching pin 40 terminates in a conical longitudinally slitted extremity 42 for the reception of a, correspondingly tapered and threaded nut 43 thereover to vary the size of the axial bore 44 provided in the clutching pin 40.

To this end, an extension rod 45 projects within the bore 44 of the clutching pin 40 for frictional engagement therein by means of the tightening nut 43 to effect the rigid connection of the beam extension rod 45 thereto which can be readily replaced should occasion demand or such become impaired through abuse in nut turning operation. It should be noted that the accuser beam 34 together withits-reduoed rod extension 45 wouldfunction exactlythe same even though these were turned orotherwise shaped from a single unit; however, such construction would be somewhat more expensive irom a production standpoint than the pressed co-axial 'flttingrelationship between the'rod's vM and Iii-serving as a, floating beam rorthe mount 32. With this arrangement, the rod extension 45 may bee!- tended or retracted within the axial bore 44 of or displaced responsive to: apredetermined-flex imparted to the. beam 3| that responds to the rotary displacement of the .revoluble'member; consequently, this efiects theextent ofadisplacement of the indicator. mechanism so adjustments.

I I6 forv the confinementof thev dial instrumentalities which will be described more fully herein after. Any back lash occasioned by the abrupt accidental release of the turning load would ordinarily jar, impairand render permanently defective the measuring instrumentalities.

' This can belargely overcome. by the beam ex tension which is. highly flexible, resilient and possessed of only ,sufficient rigidity-to actuate .the measuring instrumentalities connected thereto.- Consequently, the severe stress and strains. resulting "from any back-lash action, will be absorbed for the most part by the'flexing of the-beam extension 45 and thus protect-the measuring instrumentalities in anytype of beam device under such abnormal conditions of abusive operation. .Even though therewas an abrupt. release of load, therefore, the baclr-lash inithe aforesaid structure would be negligible and the actuator rod. 3:4-1-10-45 would notfbe called upon to withstand; any appreciable 'back-lash shock, which could, however, be. absorbed by the resilient. beam extension Ail-which is preferablyconstrueted from small diameter spring steel wire. The steel spring wire 45 is sufliciently rigid. to carry the comparatively small; load involved in actuating the indicator instrumentalities without any flex therein and yet sufficiently resilient to: absorb. any shock created injthesegmentfl'meshes with a pinion 6| mounted on a stub shaft 62 which is journalled in axial aligned bores 5:3 and provided in the casing bottom plate 53 and a bracket plate 65 mounted on the bottom plate 53 in parallel spaced relation therewith. v

The bracket plate 65 in this instance, substantially T-shaped and is held or mounted in spaced parallel relation tothe indicator casing bottom. 53.by means of threaded studs 66, in this instance three, projecting through the extremities thereof for engagement with correspondingly threaded spacer collars .61 fitted in bores 68 (Figure 14) formed in the bottom indicator casing plate 5.3. It should be observed that the fastening; collars 61 are provided with reduced collar shanks 69 serving as spacers above the bottom plate :53, thereby maintaining the T-shaped an outwardly. curved ,t

bracket '65 in spaced relation with the indicator casing-bottom plate 53. The bracket 65 also serves as a bearing for the shoulder portion 56 ofthe lever shaft 51 to insure the proper mounting of the gear segment and maintaining the meshing engagement thereof with the pinion M.

A spiral spring 10 envelops the stub shaft 62 on which the pinion 6| is mounted or integrally formed; to. normally urge or return the indicator instrumentalities to an initial position. It should be noted that one extremity of the coil spring 10 is mounted in a transverse aperture provided in the post 61 wherein a wedge .10 has been driven to establish the efiective anchor thereof (Figure 10). A calibrated dial II 1 is mounted and rests upon the peripheral shoulder 12 formed in the cylindrical collar 13 that terminates in an annular base plate 14 sized toeooperate with and serve as a complement of the flanged bottom plate 53 to permit relative 'rotation'therebetween.

abnormal, operation of, the turning head or. revoluble. member 29.

Itis' to be noted that the lever 4.81s fixed to a stub shaft 5| having a. reduced extremity 52 journalled in a. circular peripherally flanged bottom plate 53 constituting a part of the indicator casing. 'The bottom plate 53' constitutes a part of theindic'ator casing and is hired to the wall i5, of the. wrench body H by means of threaded studs- Er-Ei. centric peripheral. shoulders 56--51'-'-58 termimating in the. reduced, endf5l'over which is pressed an apertured arm 59. of, a gearsegment en; toabut against-t shoulder: 58;. 1 ,The gear" The shaft 51- has a series of con- It is to be noted that the peripheral flange of the-bottom plate 53 extends, along the top surface thereof so as to retain the collar 13 in position against Withdrawal or' removal, but permitting the relative rotation to the bottom plate ifiztopre-set or re-set the dial H for purposes that will appear more fully hereinafter. In

order that the dial H will rotate with and serve as a fixed unit of the collar 13, a resilient band 15 is disposed thereon within the peripheral edge thereof to maintain thereon a glass or other transparent crysta1 l5 fitted to the indicator casing 13. to preclude obstruction andaccess .of

foreign substances to the dial mechanism, thereby avoiding the entrance of foreign substances therein which would impair the, accuracyand operation of the indicating instrumentalities.

It will be observed that the dial His calibrated in foot pounds or foot inches.- (Figure 1) and. a metallic pin 11 ismounted therein in a position calibrated at zero. To designate the degree of flex. imparted to the beam 34. during the turning operation and converting such into foot pounds I the apertured extremity 81 of the pointer It to efiEect frictional contact therewith.

The. reduced portion of the hub 19 is then spread .asfat .84 to present an overlying flange that serves to retain the dished washer 83 in assembled relation with and frictionally against the pointer end 8| so as to enable relative rotary displacement with the hub 19 that rotates in unison with the pinion shaftextremity 80. It is to be noted that the overlying flange .84 is deformed from the material of the hub 19 after the spring disc 83 is placed in position against the apertured extremity 8| of the pointer 18. It will be apparent, therefore, that the pointer '18 will rotate with the hub "I9 and the pinion shaft extremity 88 whenever there is no obstruction in the path of the pointer 18; however, any rotation of the dial H with its casing 13 will cause the pin" to engage the pointer 18 and efiect the rotation of the latter therewith to enable pre-setting the dial and having contact established therebetween whenever any predetermined flex has been imparted to the beam 34.

Signal means are provided to indicate when the force applied in the operation of the nut turning flexes the beam 34 to the extent commensurate with the pre-setting of the dial H to the desired foot pounds which vary for any particular occasion. To this end, an electric light signal has been attached to respond to the pre-setting of the dial H and the turning of the indicator "l8 for an extent equivalent to the desired flex imparted to the beam 34. In the present embodiment, the signal means comprises an elongated tubular housing 85 that is attached to the body H by resort to internally projected studs 86 (Figure 8).

The signal housing 85 has a threaded retainer closure 81 provided at one end thereof and an electric bulb 88 in the other end that contacts a battery 89 confinedfiin the signal housing 85. Consequently, the signal housing 85 is mounted on the body together with the casing of the battery 89. An insulated electric lead or conductor Bil extends from. the insulated socket 9| of the bulb 88 to a terminal housing 92 mount ed to the bottom plate 53 of the indicator casing 13. The conductor 98 terminates in a spring.

impelled detent 93 which projects through the bottom plate 53 and effects contact with a metallic ring 94 through which the-dial pin 11 extends.

It is to be noted that the dial H is preferably though not essentially made from insulation material or for that matter may be enamelled to :provide an insulation surface so that it will not serve as an electrical conductor except through the pointer 18 when the latter engages the pin '11 and completes the circuit through the spring impelled detent 93, the body H, and the battery 89 to the bulb 88. With the use of an enamelled dial 7 I, the annular ring 94 is provided by cutting through the enamel to afford an electrical contact with the detent 93 so that the circuit Will be completed through the body of the dial H. In either case, the pin 11' contacts the annular ring 94 or the bare surface depending upon whether the dial 13 is of insulation material or has a coated enamelled surface to serve the equivalent purpose relative to the indicator casing 13. Consequently, when the dial H with its casing 13 has been rotated so that the pointer T8 is set for any predetermined unit of force, for example one hundred foot pounds, the nut turning load will flex the beam 34 and thus move the pointer 78 until the latter engages the pin 11 to complete the circuit through the electric light bulb 88, thereby energizing the signal and indicating thatthe pre-set amount at which the dial 18 has been adjusted, has been reached and no further turning movement shall be imparted through the wrench body II.

Further, the provision of the frictional clutch mount 83'. for the pointer 18, enables the latter tobe turned to any predetermined initial position before the dial has been pre-set to any desired reading so that the wrench handle II) can be manipulated from any position to gain accessibility and still have the dial II in position for convenient reading. In other words, the dial 1| cannot have its initial zero reading in longitudinal alignment with the wrench body I I, but such may be rotatively displaced to be read from any other. position depending upon the position in which the wrench must be used to gain accessibility to the nut or other fastener.

In order to preclude free rotation of the indicator with its casing 13, a spring impelled detent is mounted in the Wrench body I I (Figure 13) for. frictional contact with. the bottom flange 14 of the dial casing .13. Consequently, relative rotation of the dial H with its casing 13 will be possible only upon the direct application of turning force thereto and no rotary displacement will take place through accident or free movement such as used in effecting the turning of the fastener.

The manipulation of the handle ID by the attendant and imparting a turning movement after the head shank 38 engages the fastening expedient such as a nut, will flex the beam 34 in one direction or the other depending upon the direction of the applied force to the handle I0, and this flexing will vary proportionately to the force applied to flex the beam 34 as indicated by the dotted outline thereof in Figure 7. The beam 34 together with its reduced extension 45 is preferably turned or otherwise shaped from a high quality steel alloy that has limited flexibility and a comparatively high elastic limit so that it will uniformly flex and return to its initial position to provide accurate readings'within the range and elastic limit thereof without variation within ordinary requirements.

Any number of high quality steel alloys may be used for this purpose, and by way of example the beam 34 and its reduced extension 45 can be advantageously constructed from an oil hardened tool steel. It should be noted that the beam 34 flexes between the head 29 and the rotary mount 32, and that the movement of the rod extension 45 is one occasioned by the deflection that is a result of the flexingin the beam 34 rather than within the rod extension 45 itself. The reading of the dial reflects the deflection in the beam 34 and nothing other than mere displacement of the rod extension 45.

It will be observed from the foregoing description of an illustrative embodiment constituting the subject matter hereof, that clockwise rotation imparted to the handle [0 (viewed from Figure 1) during the engagement of the polygonal shank 38 with a nut or other fastening implement, will cause flexing of the beam 34 as shown in the dotted outline in Figure 7. This action will cause slight longitudinal displacement of the beam 34 relative to its mount 32 and the latter will simultaneously rotate for a fractional extent to facilitate the displacement of the beam ends 34-40 in opposite directions responsive to the flexing thereof. The flexing of the beam 34-40 will correspondingly displace the spring 10 which is connected to indicator possible.

instrlunentalities calibrated to the selected size or capacity-of the beam 134 -40. Then, too, if should be appreciated that the attachment of the indicator casing," with its bottom plate 53on the body wall 15 always'main- 'tains the indicator instrumen=talities in opera: tive connection with the beams 34-45, thereby rendering the cover plate -l'| removable forinspection, replacement, and cleansing purposes without interferingwith the setting and operative connection between the beam extension 45 and the indicator lever 48.

The operative connection of the indicator lever 48 to the terminal free end of the beam 34-45 also provides for the measurement of the torque at the pointof maximum deflectio'n of the torque resisting beam '34, thereby affording more accurate measurements than would otherwise be 'As stated supra, the dial H together with its casing-13 can be rotated to any desired position best suited to the View of the attendant and the pie-setting thereof to any selected maximum torque to be applied to the fastening expedient, 'vvill serve to energize the electric light v signal bulb 88 when the pointer 18 engages the pin 1-! to close the circuit to the battery '89.

With the arrangements of parts above described, a very. simple, dependable and accurate torque resisting and measuring beam 34 has been incorporated into a Wrench or other turning device without sacrificing compactness or encuim bering the turning tool with any objectionable weight. ItWill 'be observed thatshould the applied torque be released by rupture in the fastener or by accidental release at the instance of the attendant, the recoil action on the dial and its internal mechanism will notnecessarily effect the dial indicator because of the slippage made possible in the mounting thereof to the dial shaft.

Should this occur, the -recoil will take place without impairment to the dial indicator which will slip relative to its mounting shaft without any damage or impairment-to either the dial mechanism or the indicator.

feature for convenience in reading as Well as enabling presettin'g for signal indication at any predetermined torque, "since th dialindicator clutch mount affords the rapid recoiling of the dial mechanism without any effect upon the dial indicator. 1

The term pre-set" or pre setting conveys the meaning 1) that the dial H has been first rotatively positioned so that its pin 11 has been circumferentially spaced from the pointer 18 for any selected maximum torque 'tobe applied to the fastening expedient whereupon the signal 88 will be energized or (2) the dial 'I'l together with its casing is can be rotated to -any desired position best suited to the view of the attendant.. The term re-set or resetting is used tocon'v'ey the meaning that the dial pointer 18 can be manually returned to any initial preset reading or to zero, this adjustable feature also compensates for any variation due to play inthe moving parts or production differences in the indicating mech anisin, or to enable the use or the wrench for straight readings without employing the signal Various changes maybe made in the embodimen't cfthe inventionherem specifically described without departing from or sacrificing any of the advantages of tnefinvention many features thereof, and nothing hereinshall be construed as limitationsupon the invention, its concept or This is advantaeous independent "of the dial indicator resetting I ing load on said torque resisting means, said calibrated indicating means including instrumentalities forv operating a shaft, a dial rotatively mounted on said handle member relative to said shaft to enable calibration and facilitate reading of said indicatingmeans, said dial being normaL ly stationary on said handle member, a pointer frictior'i'ally. mounted on said shaft for rotation relative to or with said shaft, and a pin anchored in said dial to engage said pointer for rotative resetting responsive to' rotary dial displacement.

2. In a wrench head and handle having a calibrated indicator responsive to the torque applied in turning afastener therewith, the combination with instrumentalities for operating a shaft, a

calibrated dial mounted on said handle for rotation relative to-said shaft, a pointer on said shaft for rotation relative to or with said shaft, a 'dial ring casing enclosure attached to said dial,

. and a pin anchored on said dial for rotating said pointer relative to said shaft responsive to the rotation of said casing enclosure. v

3. In "a wrench head and handle having a can brated indicator responsive to the torque applied in t-urnin'g a fastener therewith,thecombination with instrumentalities for operating a shaft, a calibrated dial mounted on said handle for rotation relative to said shaft, a pointer frictional-1y mounted on saidshaft for rotation relative to or with said shaft, a dial ring enclosure attachedto said 'dial, a pin anchored to said dial for engaging said pointer to effect rotative resetting of said pointer relative to said shaft responsive to the rotation of said casing enclosure with said dial, signal means associated with said handle member, an electrical energy source for said signal means, and an electrical circuit including said dial pin and said pointer to energize said signal means when said dial pin and pointer contact to close said electrical circuit responsive to applying a predetermined torque to said wrench head and handle "commensurate with the presetting of said pointer on said dial.

4. In "a wrench head and handle having a calibrated indicator responsive tothe torque applied in 'tu'rhing'a fastener therewith, the combination with instrumentalities for operating a shaft, a

calibrated dial mounted on said handle for rotation relative to said shaft, a pointer frictionally mounted on said shaft for rotation relative to or with said shaft, and api-n anchored in said dial to engage the free extremity of said pointer for rotative resetting responsive to rotary dial displacement. 1

5. In a wrench head and handle having a calibrated indicator responsive to the torque applied in turning a fastener therewith, the combination with instrumentali-ties' for operating a shaft, a calibrated dial mounted for rotation 'on said handle relative to said shaft, a casing for said dial journalled on said wrench for effectin the rotary support thereof relative to said shaft, a

'pointenmounted on said shaft, and means on said dial in-the path of said pointer for resetting the latter responsive to turning said dial casing.

6. In a torque wrench, the combination with a handle member, of a work turning member operatively connected to said handle member, torque resisting means interposed between said handle member and said work turning member, calibrated measuring means operatively connected to said torque resisting means to measure the turning load transmitted by said work turning.

member to said torque resisting means, said calibrated measuring means including a dial and indicator mounted on said handle member, said dial and indicator being both mounted for movement relative to each other and to said handle member, and means for presetting the position of said dial and indicating means relative to each other and said handle member without influencing the operative connection of said calibrated means with said torque resisting means.

7. In a torque wrench, the combination with a handle member, of a work turning member operatively connected to said handle 'member, torque resistin means interposed between said handle member and said work turning member, calibrated measuring means operatively connected to said torque resisting means to measure the turning load transmitted by said work turning member to said torque resisting means, said calibrated measuring means including a dial and indicator mounted on said handle member, said dial and indicator being both mounted for movement relative to each other and to said handle member, and flexible yielding means interposed betweensaid torque resisting means and said callbrated measuring means to unyieldingly transmit normal turning loads therebetween and to yield responsive to the transmission of abnormal turning or shock loads, thereby avoiding injury to said calibrated measuring means.

8. In a torque wrench, the combination with an elongated wrench body member, of a handle member extending from one end of said body member and of substantially lesser length then said body member, a work turning member operatively connected to said body member proximate to the other end thereof, torque resisting means between said handle member and said Work turning member in said body member, calibrated measuring means operatively connected to said torque resisting means to measure the work turning load responsive to applying force to said handle member, said calibrated measuring means including a dial and a pointer mounted for movement simultaneously or relative to each other, and means responsive to said dial movement means for resetting said pointer with said dial without influencing the operative connection between said torque resisting means and said calibrated measuring means.

9. In a torque wrench, the combination with a handle member, of a turning head member operatively connected to said handle member, torque resisting means interposed between said handle member and said turning head member,

calibrated measuring means operatively connected to said torque resisting means to measure the load on said turning head member, said cell. brated measuring means including instrumentalities for operating a shaft, indicating means on said shaft, a dial and easing mounted for rotation relative to said shaft about their common axis to enable resetting and facilitate. reading of said indicating means, said dial and casing being normally stationary on said handle mem er ative to said shaft for rotation independently thereof, said indicating means being mounted on said shaft for rotation relative to or with said shaft, and means on said dial to enable corresponding or relative movement between said dial and indicating means responsive to rotating said casing.

10. In a torque wrench, the combination with a handle member, of a turning head member operatively connected to said handle member, torque resisting means interposed between said handle member and said turning head member, calibrated measuring means operatively connected to said torque resisting means to measure the load on said turnin head member, said calibrated measuring means including instrumental ities for operating a shaft, indicating means on said shaft, a dial casing rotatively mounted on said handle member for rotation relative thereto about the common axis of the shaft and casing to enable resetting and facilitate reading of said indicating means, said dial and casing being normally stationary on said handle member relative to said shaft for rotation independently thereof, said indicating means being mounted on said shaft for rotation relative to or with said shaft, and a pin on said dial in the path of said indicating means to enable relative movement between said indicating means and shaft responsive to rotating said casing.

11. In a torque wrench, the combination with a handle member, of a turning head member op eratively connected to said handle member, torque resisting means interposed between said handle member and said turning head member, calibrated measuring means operatively connect ed to said torque resisting means to measure the load on said turning head member, said cali brated measuring means including instrumentalities for operating a shaft, indicating means on said shaft, a dial casing rotatively mounted on said handle member for rotation relative thereto about the common axis of the shaft and casing to enable resetting and facilitate reading of said indicating means, said dial and casing being nor mally stationary on said handle member relative to said shaft for rotation independently thereof. said-indicating means being mounted on said shaft for rotation relative to or with said shaft, and flexible yielding means interposed between said torque resisting means and said calibrated measuring means to unyieldingly transmit nor mal turning loads therebetween and to yield responsive to the transmission of abnormal turning or shock loads, thereby avoiding injury to said calibrated measuring means.

12. In a torque wrench, the combination with a handle member, of a work turning head member in said handle member, torque resisting means interposed between said handle member and said work turning head member, said torque resisting means including an elongated rod anchored at one extremity thereof to said work turning head memben-a highly flexible axial extension on the other extremity of said rod, and

torque indicating means operatively connected to the free extremity of said highly flexible rod extension which is displaced responsive to applying force to said handle means, said flexible rod extension being sufficiently inflexible to transfer normal loads on said work turning head member to said torque indicating means and sufliciently flexible to yield responsive to abnormal loads to serve as shock absorbing means, said torque indicating means including instrumentalities for shaft to enable calibration and facilitate reading of said indicating means, said dial being normally stationary on said handle member, and a pointer mounted on said shaft for rotation with said shaft.

13.'In a torque wrench, the combination with a handle member, of a work turning head member journalled in said handle member, torque resisting means interposed between said handle member and said work turning head member, said torque resisting means including an elongated rod anchored atoneextremitythereof to said work turning head member, a highly flexible axial extension on the other extremity of said rod, torque indicating means operatively connected to the free extremity of said highly flexible rod extension which is displaced responsive to applying force to said handle means, said flexible rod extension being sufficiently inflexible totransfer normal loads on said work turning head member to said torque indicating means and sumciently flexible to yield responsive to abnormal loads to serve as shock absorbing means, said torque indicating means including instrumentalities for operating a shaft, a dial rotatively mounted on said handle member for movement relative to said shaft to enable calibration and facilitate reading of said indicating means, said dial being normally stationary on said handle memben'and a pointer frictionally mounted on said shaft for rotation relative to or with said shaft.

14, In a torque wrench, the combination with a handle member, of a work turning head member journalled in said handle member, torque resisting means interposed between said handle mem ber and saidwork turning head member, said torque resisting means including an elongated extension which is displaced responsive to apply- I ing force to said handlemeans, said flexible rod extension being sufficiently inflexible to transfer normalloads on said'work turning head member to said torquev indicating means and sufiimounted on said handle member for movement relative to said shaft to enable calibration and on said handle member, an electrical energy source for said signal, and an electrical circuit including said dial pin and pointer to energize said signal when said dial pin and pointer engage responsive to applying a predetermined torque to said turning head commensurate with the'presetto said torque indicating means and sufficiently flexible to yield responsive'to abnormal loads to serve as shock absorbing means, said torque indi- 'cating means including instrumentalities for operating a shaft, a dial rotatively mounted on I relative to or withsaid, shaft, and a pin anchored in said dial to engage the free extremity of the pointer for rotative resetting responsive to rotary dial displacement. i

15. In a torque wrench, the combination with a handle member, of a work turning head memv6 ber journalled in said handle member, torque resisting means interposed between said handle member and said work turning head member,' said torque resisting means including an elongated rod anchored at one extremity thereof to said work turning head member, a highly flexible axial extension on the other extremity of said rod, and

torque indicating means operatively connected to the free extremity of said highly flexible rod ting of said torque indicating means.

16. In a torque wrench, the combination with a handle member, of a work turning head member operatively connected to said handle member, torque resisting means interposed between said handle member and said work turning head nected to the other extremity of said rod, calibrated indicating means on said handle member and operatively connected to an extremity of said highly flexible rod extension to measure the displacement of said torque resisting means, said flexible rod extension being sufficiently inflexible to transfer normal loads on said work turning member to said torque indicating means and sufficiently flexible to yield responsive to abnormal loads to serve as shock absorbing means, said calibrated indicating means including instrumentalities for operating a shaft, a dial disposed relative to said shaft, and a pointer mounted on said shaft for rotation with said shaft.

17. In a torque wrench, the combination with a handle member, of a turning head member operatively connected to said handle member, torque resisting means interposed between said handle member and said turning head member, said torque resisting means including a rod' extending from said turning head member for displacement responsive thereto, a highly flexible spring wire extension longitudinally adjustable on the other extremity of said rod, calibrated indicating means on said handle member and operatively connected to an extremity of said highly flexible rod extension to measure the displacement of said rod responsive to said turning head member, said flexible rod extension being sufficiently inflexible to transfer normal loads on said turning head member to said calibrated indicating means, said calibrated indicating means including instrumentalities for operating a shaft, a dial disposed relative to said shaft, and a pointer mounted on said shaft for rotation therewith responsive to the displacement of said rod and extension.

' KENNETH R. LARSON.

GEORGE M. WALRAVEN. 

